Convertible printing press



Jan. 20,1942. v w. w. DAVIDSON 2,270,272 I CONVERTIBLE PRINTING PRESS Filed July 25 1940 V Q Y INV-ENTOR; Wjl'aozifa/dfiazudsolz M Patented Jan. 20,1942

UNITED CONVERTIBLE ram'rme mass William Ward Davidson, Evanston, Ill. Application my 25, .1940, Serial No. 347,454

l 01' my copending application, Serial No, 293,554,

iiled September 6, i939, and relates to printing presses generally, and more particularly to presses which are convertible to perform diflerent printing processes. The disclosur made in the above copending application is hereby incorporated and made a part of the present application.

Three common classes of printing processes are: lithographic, intaglio, and type printing. With more and greater uses being made of comfmercial printing of these various types, it is important that presses be constructed and designed for rapid and easy conversion.

In order. however, to provide convertible printlng presses, the question of interchangeability oi. printing'media and the question of inking and ink distribution are important problemsi In the present invention, I provide an improved convertible press wherein the blanket and type segcylinder is utilized as an ink conveying or transferring surface in the train of rollers that are employed to supply the type segment with ink. My invention is illustrated herein as incorporated in a three cylinder press.

Another purpose oi the invention is to provide a press that may be converted to perform different classes of printing processes without need for changing the inking mechanism of the press.

Another purpose of the invention is to provide a cbnvertible press which is characterized by a minimum number of alterations that are needed to convert the press, and the rapidity with which the conversion maybe accomplished.

Moreover, I provide a convertible press having the above characteristics, that prints the paper upon the same' side, preferably the top side, whether converted to one'form or the other; thereby minimizing the necessity for changing the position or operation or associated parts, such as the feed and the delivery mechanisms. 1

Other objects willflbecomeapparent from the drawing, the description relatingjhereto and the .sippended claims.

Referring now, to the drawing: .Fig. 1 illustrates'a'three cylinder rotary press set up 'ioroflsetlithosraphic printing; p

Fig.2 illustrates the press-shown inFig. l as converted for direct type printing;

Fig. -3 shows a fragment of the plate cylinder when constructed to use plate;and

a spacer beneath the 25 plate cylinder l2.

from the conveyor board I by the feed rollers 6 a s. (not shown).

The present inventibn is a continuation in -part v Fig. 4 is a view corresponding to Fig. 3 but she g a resilient ink distributing surface substituted for the plate and spacer.

Broadly speaking without changing the ink- 5 ing characteristics of the inking unit or its posltion, I convert the blanket cylinder of an oflset lithographic couple into a lithographic or type cylinder and utilize the plate on the plate cylinder of the couple as one of the rollers in the .10 train of rollers employed for inking the type 1 upon the printing cylinder.

In Figs. 1 and 2, a three cylinder pressis shown, wherein conversion from the offset lithography shown in Fig. 1 to the direct printing in Fig. 2, is accomplished by replacing the etched plate with an unetched plate. Form rollers, pref erably surfaced with a resilient, material, are then added to cifiivey ink placed up n the unetched plate to the type upon the printing cylinder and an eccentric means is employed to lift ment are preferably interchangeable upon one a cylinder, and the lithographic plate of another the cylinder enoughto clear the type. V

I More particularly, in Figs. l and 2, the blanket cylinder of a threecylinder lithographic press is shown at III, intermediate the platen II and Blanks of paper I3 are fed l5 which are synchronized to feed a sheet to the bite of thecylinders between the'platen II and blanket III. A leading overlap of-the sheet i is preferably provided at the gap lli's'othatthe stripper I! may be tilted, if desired, into-the direct it onto the delivery table l8. w The ink applying rollers are indicated at 3.1 and comprise the fountain roller 2l,.the.ductor \roller 22, the distributor roller 2! and the ink form rollers 24. The form rollers 24 are pivotally mounted to runin contact with the distributing roller 23 constantly by arms 25 mounted for 4" movement about the shaft supporting the-'dis-' In this way, if there is any tributing roller 28. I 4 variation in the distance desired or required between the distributing roller 23 and the plate cylinder [2,- it can be allowed for ior. taken up by relative movement of the form rollers 24,

' toward or away from each other, in the space afforded between the distributing rolier and the plate cylinde v The water damping mechanism" comprises the fountain roller 28, the water ductor roller 21, the

water distributing, roller 28 and the water iorm roller 2!. The "form rollers 24 and 29 may be liited separately to clear the plate whenever desired by suitable hand orautomatically operated g pto catch the leading edge of the sheet'andl-The plate 3| is shown mounted upon the pla cylinder I! as clamped at the leading edge 3| and drawn taut over the 'bed 32 by a tensioning clamp device 33 disposed at the trailing edge thereof.

I prefer to mount the cylinder I'2 so that its center of rotation is slightlyeccentric to pivotal quite easily by persons comparatively unskilled with printing presses. The inking mechanism remains physically unchanged. The shot bolt 44 is retracted and the arm '43 located at the deing circumference is indicated by the numeral "and the shaft is provided with integral ec centric end studs 4!, that are iournaled in the side frames. A plate "is keyed to one of the studs 4| at the outer ends thereof and has fas-' tened thereto a throw arm 43 which is held in either one of two positions-as shown by a spring pressshot bolt 44. The arm 43 is shown in its lowered position in Fig. lwhereit rests against an adjustable stop 45 asheld there resiliently by a spring 46. In Fig. 2, the arm is shown in its'upper position as supported by the shot bolt 44, after the arm 43 has been raised manually and'the shot bolt inserted under the end thereof.

3 When in its lowered position, the arm 43'moves :the shaft 40 to hold the cylinder l2 against the blanketfcylinder It with the required blanket inking pressure, and when in its raised position,

vth'e arm 43 rotates the'shaft 40 to lift the cylinder l2 enough to clear the type segment 39 upon the cylinder l0.

Whether: the arm and the cylinder H are disposed in their upper position or in their lower position, the ink rollers 24 accommodate for the relative displacement present between the roller 2| and distributing roller 23. The rollers 24 remain in contact with the plate by moving closer towards each other to fill the space between the distributing roller and theplate if the space is increased, or separate to accommodate themselves to the space if the space is decreased.

Whenever it is desirable to convert the embodiment-illustrated in Fig. 1 into a direct or type printing press, the blanket 34, shown in Fig. l, isrem'oved from the blanket cylinder I II and a cast type plate 35, or the like, is secured -to the cylinder M. The plate 30, in Fig. 2, then becomes a distributing surface for the ink supplied thereto-by the rollers 24. which hitherto served as form rollers. The plate '30 may be the same plate without any etching solution supplied thereto, or a different plate which has not been etched; In either event, the water form roller 29 is raised so that it will not contact the plate.

' In orderto transfer the ink from the plate so,

I prefer to employ two pairs of rollers 36 and 31, preferably surfaced with resilient material, which serve as distributing and form rollers respectively, for the type segment 35. The diameter of these rollsare preferably the same, al-

, though not necessarily so, whereby they may be adapted to be converted to ofi'set lithographic printing, the conversion'may be had "readily and sired point. The segments upon cylinder," are interchanged, the rollers 38 and 31 are added or removed as required, preferably through-inclined slots (not shown) in the side frames, the water form roller 29 is raised or lowered as desired, and the form damping-roller, 29 is raised. No other changes are needed to convert the press from' one form of printing to another and in either case the blank sheets are printedon the same side which, in this instance, is upon the upper side.

It will be appreciated that cylinders III and I2 are preferably gear driven relative to each other and the relative drive may be maintained through a conventional Oldham coupling (not shown).

Furthermore, I prefer to mount the platen l'l so that it will be thrown out whenever a sheet is skipped by the feed and whether a cast type segment upon the cylinder ID or other means for direct printing is used in the conversion, the working diameter in the cylinder construction is determined in relation to the pitch line of the gear teeth of the two coupled cylinders so that other forms may be substituted for the blanket in the conversion without altering the operations of the printing couple.

In event it is not desired to separate the plate and blanket cylinders, it will beappreciated that within the object of not having two metal ink distributing surfaces running against each other, the plate cylinder may be machined to a smaller radius to receive a resilient or composition ink distributing covering 41 (Fig. 4) in substitution for the plate which is thick enough to bring the surface thereof up to the pitch line of the gears. With this arrangement the plate 30, when mounted on the plate cylinder, is provided with invention and disclosed the manner in which they are believed to function and operate in their best and preferred form, it will be apparent to those skilled in the art, that various uses, modificatlons, and changes may be made therein Hi I without departing from the spirit and substance of the invention, the scope of which is com mensurate with the appended claims.

What is claimed is:

l. A combination oilset lithographic and direct printing press comprising cooperating lithographic, platen, and blanket surfaces, meansinterchangeable with the blanket surface to provide a direct printing surface, means for varying the distance between the blanket surface and the lithographic surface, an inking mechanism, and means for using the lithographic surface as an ink form surface to transfer ink from the inking mechanism to the direct printing surface including removable rollers disposed between the lithographic surface and the direct printing surface.

2. A convertible printing press comprising ;a plurality of cooperating cylinders, interchangeable blanket and direct printing surfaces for one of the cylinders, a platen surface upon another cylinder running in contact with the first cylinder to provide a printing couple, a plate, means for varying the distance between the plate and face or the lithographic surface theblanket surface to provide a clearance therebetween, and means for transferring ink from the plate to the direct printing surface without direct contact between the plate and the direct printing surface. w

3. A convertible printing press comprising a cylinder having a blanket surface disposed above blanket on said blanket cylinder for'providing a\ direct printing surface, an inking mechanism adapted to supply ink to the lithographic cylinder, and means for converting the lithographic cylinder into an ink distributing cylinder to supply ink to the direct printing surface when the press is doing direct printing.

5. A convertible printing press comprising a cylinder having a blanket surface disposed above a platen, a plate surface cooperating with the blanket surface for thetransfer of ink, means for inking the plate surface, means for converting the plate surface into an ink form surface, and means interchangeable with said blanket surface for providinga direct printing surface.

6. A printing press comprising a lithographic surface, a platen surface and 'a blanket surface being capable of engaging both the lithographic surface and the platen surface-and means for converting the press from an offset lithographic to a direct printing press by interchanging a direct impression printing surface with a blanket. surface and by interchanging an ink formsurface for the lithographic surface, and a single inking mechanism supplying ink to the ink form surdepending upon which surface is in use.

I. A printing press comprising a, lithographic surface, a platen, a blanket cylinder running in contact with platen, inking means for the lithographic surface, mean for converting the blanket cylinder into a direct impression cylinder, and means for converting the lithographic surface into an ink form surface for transferring ink from the inking means to the direct impression cylinder.

8. A convertible printing press comprising a blanketcylinder anda platen, a bianket for the cylinder, a second cylinder having a bed sur-' face, a plate for the bed surface, a composition covering interchangeable with the plate, means for establishing a substantially constant printing'radius for both the plate and the covering,

a direct printing segment interchangeable with th blanket, and inking means in contact with either the plate or the covering, whichever is the plate receiving cylinder.

9. A convertible printing press comprising a platen and a cylinder having a blanket surface, a platesurface adapted to run against the blanket surface, means for inking the plate surface, means interchangeable with said blanket surface for providing a direct printing surface, means for varying the distance between the blanket surface and the plate surface to provide a clearance therebetween, and means for converting the plate surface into an ink distributing surface including a pair of ink transfer rollers one of which contacts the'ink distributing surface and the other contacting the direct printing surface.

10. A cnvertible printing press comprising a platen cylinder and a cylinder provided with interchangeable blanket and. direct printing surfaces, a third cylinder provided with a bed,

means for supporting a plate on the bed including a spacer, an inking mechanism adapted to engage and transfer ink directly to the plate on the third cylinder, and means for converting said third cylinderinto an ink distributing surface by removing-theplate and spacer and sub stituting a resilient ink transfer covering whereby ink is transferred from the inking mechanism to the ink distributing surface on the third cylinder and thence to the direct printing surface when the press is doingdirect printing.

WILLIAM WARD DAVIDSON.

said lithographic surface and 

